There are different devices, like for example measuring instruments, which are equipped with a replaceable probe head.
An embodiment of a conventional measuring instrument comprises a probe head, which can be connected by means of spring action with a probe system.
There are also examples of probe heads, which are fastened by means of permanent magnets to a probe system of a measuring instrument. An appropriate example is described in the German utility model DE-GM 7400071.
A further measuring instrument is presented in the U.S. patent specification U.S. Pat. No. 5,755,038. This special measuring instrument is characterised by the fact that it provides a probe head, which is connected to a probe system by permanent magnets. A similar approach is described in the PCT application WO 03/087708.
A further example of a measuring instrument with replaceable probe head is to be inferred from the German patent specification DE 3320127 C2. There a measuring instrument is described, whose probe head is fastened by means of a combination of a permanent magnet and an electromagnet.
The replaceable probe heads should be as fast and uncomplicatedly removable as possible. In addition, it is important that a measuring instrument is able to differentiate different probe heads from each other, since for example depending upon the kind of the actually used probe head other parameters find application during the evaluation of measuring signals. It is also conceivable that dependent on the form and/or size of the probe head other approaching paths and courses of motion of the probe head are used.